Draft gear for railway draft rigging



June y30, 1959 A. E. DENTLER 2,892,551

A. E. DENTLER June 30, 1959 Filed June 18, 1956 imm lill/lll?! Inventor" n ola' E: penile?" United States Paten i 2,892,551r j DRAFT GEAR Fon RAILWAY nRAFr incenso Arnold E. Dentler, La GrangerPark, Ill., assignor to W. H. Miner, Inc., Chicago, Ill., a corporation of Delaware Application June 18, 1956, Serial No. 592,098

2 Claims. (Cl. 213-40) This invention relates to draft gear for railway draft rigging.

It is a main object of the invention to provide a selfcontained rubber draft gear of simple construction and containing a minimum number of parts.

Another object of the invention is to provide a rubber draft gear in which the rubber is stressed simultaneously in shear and compression by operations of the gear.

Further objects of the invention not specifically mentioned here will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which:

Figure 1 is a front elevational view of the gear;

Figure 2 is a transverse cross sectional view of the gear taken substantially along the line 2-2 of Figure 3, looking in the direction of the arrows; and

Figure 3 is a longitudinal cross section through the gear, taken along the line 3-3 of Figure 1, looking in the direction of the arrows.

The draft gear of the present invention consists of a metallic casing A formed of cast steel and containing a rubber unit B and a plunger C likewise formed of cast steel. The rubber unit B is bonded to the interior surfaces of the walls of the casing A and to the exterior surface of the plunger C.

The casing A, which is shown as of hexagonal cross section, consists of a back wall and side walls 11, extending forwardly therefrom and terminating in the open front end of the casing. The inner surfaces 11 of the side walls 11 are tapered to provide within the casing a cavity that has its largest transverse dimension at the open end of the casing and its smallest transverse dimension adjacent the closed end thereof.

In the example shown, the side walls 11 of the casing are provided with two openings 12 disposed adjacent to the closed end 10 of the casing.

The plunger C, preferably also formed as a steel casting, is tapered from a closed inner end 13 to a larger open end 14 that projects out of the open end of casing A. The plunger C, in the gear shown by way of example, is of hexagonal cross section.

The mass of rubber B is molded in the casing and bonded to the walls thereof and to the plunger C, the plunger being withdrawn during the molding so that its inner end 13 is positioned as indicated in phantom lines. Openings 12 are blocked by suitable plugs, not shown, and extend inwardly to define cavities 15. Likewise, a suitable closure member, not shown, is placed about the end 14 of the plunger C and in engagement with the open end of the casing A to close such open end and to define a plunger encompassing recess 16. The rubber unit or mass B, during molding and vulcanization is bonded to the inner surfaces of the casing and to the plunger.

The gear thus formed is a unitary structure and when it is inserted into the pocket and yoke of a draft rigging,

j 2,892,551 Patented J une` 30, 1959 rice plunger C is moved inwardly of the casing into the position in which it is shown in full lines in Figure 3. The closure member (not shown) surrounding the plunger C andthe plug members (not shown) fitting within the openings 12 are preferably of such shapes as to impart the configurations of cavities 15 and recess 12 as shown in full lines in Figure 3, wherein the rubber unitv B is in partially stressed condition. The usual front fol-` lower D of the draft rigging and rear follower E thereof maintain the plunger in this position. This movement of the plunger inwardly of the casing builds up in the rubber an initial resistance of desired value, which value may be varied by varying the distance from the back Wall 10 of the casing of the inner end 13 of the plunger during insertion and molding of the rubber.

As the plunger C is moved inwardly of the casing during an operation of the gear, the rubber B is stressed simultaneously in shear and in compression. The distribution of the stresses between shear and compression can be varied by varying the angle of taper of the walls 11 of the casing and of the plunger C. As shown in the drawing, the taper of the walls 11 is much less than that of the plunger and the stress in compression is therefore less. By increasing the taper of the walls 11 so that they be parallel or substantially parallel to the plunger, the stresses imposed on the rubber B in compression will be correspondingly increased.

Inward movement of the plunger C moves the inner end 13 thereof toward the rear wall 10 of the casing and forces the rubber therebetween to move outwardly toward the openings 12. The rubber displaced by compression between the plunger and casing walls likewise is moved toward and into the cavities 15 and openings 12. Similarly, during compression, rubber adjacent to the recess 16 will ow or be displaced into such recess 16. When the forces forcing the plunger inwardly of the casing are removed, the gear is returned to the position shown in Figure 3 by the restoration of the rubber.

From the foregoing it will be seen that the gear of the present invention consists of a minimum number of parts and is arranged to stress the mass of rubber which it contains simultaneously in shear and compression. While in the example shown the casing and plunger are of hexagonal cross section, modifications of this particular shape may be made within the teachings of the invention.

Having thus complied with the statutes as shown and described, a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims,

What I claim is:

1. A draft gear for railway draft rigging comprising: a metallic casing open at one end and closed at the other end; a plunger disposed centrally in said casing, spaced from the closed end and projecting out of the open end thereof; a mass of rubber filling the space between the plunger and casing and bonded to the plunger and casing for resisting movements of the plunger inwardly of the casing; lateral openings provided in the casing adjacent its closed end; preformed cavities in the rubber mass within the casing and merging with the lateral openings in the casing; the plunger having a rounded nose portion to thereby direct the displacement of the rubber disposed between such nose portion and the closed end of the casing laterally into said preformed cavities and into said openings as the plunger is displaced inwardly of the caslng.

2. A draft gear for railway draft rigging comprising: a tubular casing open at one end and closed at the other end, inner side wall surfaces of the casing convergent toward the closed end thereof; a tapered plunger disposed centrally in said casing, spaced from the closed end and: projectingvout ofthe open end thereof; a mass of rubber `filling` the space between the plunger and casing and bonded to the plunger and casing for resisting movements of the plunger inwardly of the casing; lateral openings: provided.- in the casing adjacent its closed end;

preformedy cavities inf the rubber mass within the casingY nose portion and the closed endvof the casing laterally into 10 saidV preformed cavities and into said openings as the' tapered plunger is displaced inwardly of the casing.

ReferencesCit'ed in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS France Oct; 2, 1933. 

